The present invention relates to an improved canopy frame for use on umbrellas which have their canopies structured in various shapes, making the external appearance of umbrellas dexterous, attractive and interesting. The frame is comprised of a main shaft, an upper sliding notch, a lower sliding notch, multiple positioning ribs, multiple upper spreaders, multiple upright ribs, multiple upper angle-forming clamps, multiple auxiliary stretchers, multiple lower spreaders and multiple clamping pieces. There are two positioning holes on the main shaft for the fixing of the upper and lower sliding notch and at the top end of the main shaft is disposed the fixed notch. The upper and lower sliding notch mounted consecutively on the main shaft under the fixed notch. One end of each positioning rib is connected to the fixed notch and the other end is associated with an end hinge point of an upper angle-forming clamp. One end of each upper spreader is fixed to the upper sliding notch and the other end is engaged with the middle hinge point of an upper angle-forming clamp. One end hinge point of each angle-forming clamp is coupled to one end of each upright rib to which is mounted a clamping piece at the other end. The upright rib has a hinge projection at one end to which one end of each auxiliary rib is connected and the other end is fixed to an end hinge point of a lower angle-forming clamp, and each lower angle-forming clamp is associated with a folding rib. Thereby when a canopy is mounted to the frame, umbrellas of various shapes can be obtained.
The improved canopy frame is easily converted into different kinds of shapes so as to make umbrellas produced in dexterous forms for commercial advertisements or just to be used as common umbrellas, which can better protect people from getting wet by rain.
In general, common umbrellas are all made to have a simple canopy frame including a main shaft on which a runner is slidably moved to get a frame to stretch open, and a canopy attached to the frame is extended in an arch shape without any variations for decades. Such a structure is not ideal enough to permit commercial advertisements to be printed on the canopy in one aspect, and such an umbrella is not good enough to protect a person under the umbrella from getting wet by rain cast in slant directions.